Delhi air quality improves a shade, still ‘very poor’

High volume of airborne particulates continues to keep Delhi’s air quality ‘very poor’, a shade better than ‘severe’, continuing the trend observed since December 6.

The National Air Quality Index (NAQI) of Central Pollution Control Board (CPCB) puts the 24-hour-average AQI at 340 — anything beyond 400 is considered severe as per the categorisation. Experts say although little differentiates the two categories, the general intensity of pollution in Delhi during winters is such that anything less than ‘severe’ is considered a relief.

All but one monitoring station of Central agency SAFAR (System of Air Quality and Weather Forecasting and Research) recorded very poor air.

Only the Lodhi Road Centre had PM 10 as ‘moderate’ and PM 2.5 as ‘poor’. CPCB parameters say that one may develop respiratory illness on prolonged exposure to very poor air quality while severe AQI affects healthy people and seriously impacts those with existing diseases.

SAFAR said the 24-hour-average (rolling) of PM 2.5 and PM 10 were 137 and 290 micrograms per cubic metre respectively.

PM 2.5 and PM 10 are ultrafine particulates — products of vehicular emissions, road and construction dust, and diesel generators among others — which routinely violate the prescribed standards of 60 and 100 micrograms per cubic metre in Delhi daily. The Delhi government held a review meeting where the average concentration of particulate matter from November 1 to December 11 was also discussed.

“In the meeting, Delhi Pollution Control Committee officials informed that there is no significant increase in levels of particulate matter. Environment Minister Imran Hussain said in view of dipping night temperature, controlling of garbage and biomass burning needs to be emphasised,” a government spokesperson said.